using System;

using System.Collections.Generic;

using Newtonsoft.Json;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var testString = "At First Level|1 - At First Level|     2 - Child of 1|     3 - Child of 1|          4 - Child of 3|     5 - Child of 1|last - At First Level";

        var rdo = RelatedDataObject.CreateFrom(testString);

        var jsonString = JsonConvert.SerializeObject(rdo, Formatting.Indented);

        Console.WriteLine(jsonString);

    }

}

​

​

public class RelatedDataObject

    {

        public string Record { get; set; }

        public IEnumerable<RelatedDataObject> SubRecords { get; set; }

​

        private class ParentChildId

        {

            public string Value { get; set; }

            public int Parent { get; set; }

            public int Id { get; set; }

        }

​

​

        public static IEnumerable<RelatedDataObject> CreateFrom(string value)

        {

            var list = new List<RelatedDataObject>();

            if (string.IsNullOrWhiteSpace(value))

                return list;

            if (!value.Contains("|"))

            {

                list.Add(new RelatedDataObject { Record = value });

                return list;

            }

​

            var items = new List<ParentChildId>();

            var depthList = new Stack<KeyValuePair<int, int>>();

            depthList.Push(new KeyValuePair<int, int>(0, -1));

            var index = 0;

            foreach (var item in value.Split('|'))

            {

                var currentIndentation = item.TakeWhile(Char.IsWhiteSpace).Count() / 5;

                var depthItem = depthList.Pop();

                var parent = -1;

                if (currentIndentation == 0)

                {

                    depthList = new Stack<KeyValuePair<int, int>>();

                    depthList.Push(new KeyValuePair<int, int>(0, -1));

                    depthList.Push(new KeyValuePair<int, int>(currentIndentation, index));

                }

                else if (depthItem.Key == currentIndentation)

                {

                    parent = depthList.Peek().Value;

                    depthList.Push(new KeyValuePair<int, int>(currentIndentation, index));

                }

                else if (depthItem.Key > currentIndentation)

                {

                    while (depthItem.Key > currentIndentation)

                    {

                        depthItem = depthList.Pop();

                    }

                    parent = depthList.Peek().Value;

                }

                else if (depthItem.Key < currentIndentation)

                {

                    parent = depthItem.Value;

                    depthList.Push(depthItem);

                    depthList.Push(new KeyValuePair<int, int>(currentIndentation, index));

                }

​

                items.Add(new ParentChildId { Value = item.Trim(), Parent = parent, Id = index++ });

​

            }

            foreach (var item in items.Where(t => t.Parent == -1))

            {

                list.Add(new RelatedDataObject { Record = item.Value, SubRecords = GetChildren(items, item.Id) });

            }

​

            return list;

        }

​

        private static IEnumerable<RelatedDataObject> GetChildren(IEnumerable<ParentChildId> records, int parentId)

        {

            if (!records.Any(t => t.Parent == parentId))

                return null;

            var childRecords = records.Where(t => t.Parent == parentId);

            var recs = childRecords.Select(t => new RelatedDataObject { Record = t.Value, SubRecords = GetChildren(records, t.Id) });

            return recs;

        }

​

    }